Correlation of Perfusion Index Change and Analgesic Efficacy in Transforaminal Block for Lumbosacral Radicular Pain

Abstract

Transforaminal epidural injection is used to treat radicular pain. However, there is no objective method of assessing pain relief following transforaminal injection. Perfusion index is a metric for monitoring peripheral perfusion status. This study evaluates the correlation between perfusion index change and analgesic efficacy in transforaminal blocks for lumbosacral radicular pain. We retrospectively analyzed data of 100 patients receiving transforaminal block for lumbosacral radicular pain. We assessed perfusion index before treatment and at 5, 15, and 30 min following the block. We defined responders (group R) and non-responders (group N) as those with ≥50% and <50% pain reduction, respectively, 30 min following block. Clinical data and perfusion index of the groups were analyzed. Ninety-two patients were examined, of whom 57 (61.9%) and 35 (38.0%) patients reported ≥50% and <50% pain reduction, respectively. Group R had a significantly higher perfusion index change ratio 5 min following the block (p = 0.029). A perfusion index change ratio of ≥0.27 was observed in group R (sensitivity, 75.4%; specificity, 51.4%; AUC (area under the curve), 0.636; p = 0.032). A perfusion index change ratio of ≥0.27 at 5 min after block is associated with, but does not predict improvement in, pain levels following lumbosacral transforaminal block.

Correlation between paravertebral spread of injectate and clinical efficacy in lumbar transforaminal block

“…The inclusion criteria were as follows: (a) a primary diagnosis of lower back pain radiating to the lower limbs and (b) a cross-sectional imaging study (either computed tomography [CT] or magnetic resonance imaging [MRI]) of the lumbosacral spine in patients diagnosed with spinal stenosis or herniated nucleus pulposus (HNP) 14 . The exclusion criteria included any history of lumbar surgery; lumbar neuroplasty; neoplastic diseases; peripheral vascular disease affecting pain, perfusion index and/or cold sensation; or use of medications affecting the vascular system 14 . We also excluded injections at L5, as the clinical response to the lumbar sympatholytic effect is known to be significant above the level of the L4 vertebral body 10 , 15 .…”

“…We also excluded injections at L5, as the clinical response to the lumbar sympatholytic effect is known to be significant above the level of the L4 vertebral body 10 , 15 . The lesion level for transforaminal injections was selected on the basis of clinical manifestations, physical examination, and review of imaging studies 14 . Lesion severity was categorised as one of three different degrees (mild, moderate, or severe) by reviewing imaging data 14 .…”

Analysis of Subdural Injection During Lumbar Interlaminar Epidural Injection in Failed Back Surgery Syndrome

“…The inclusion criteria were: (a) over six months had elapsed since the patients’ lumbar spinal surgery; (b) a primary diagnosis of lower back pain radiating to the lower limbs; (c) a cross-sectional imaging study (either computed tomography or magnetic resonance imaging) of the lumbosacral spine among patients diagnosed with spinal stenosis or herniated nucleus pulposus [ 17 ]. The exclusion criteria included lumbar vertebroplasty, lumbar neuroplasty, neoplastic diseases, peripheral vascular disease, or the use of medications affecting the vascular system [ 17 ]. The epidural injection level was chosen based on clinical manifestations, physical examination, and review of the imaging studies [ 17 ].…”

“…The exclusion criteria included lumbar vertebroplasty, lumbar neuroplasty, neoplastic diseases, peripheral vascular disease, or the use of medications affecting the vascular system [ 17 ]. The epidural injection level was chosen based on clinical manifestations, physical examination, and review of the imaging studies [ 17 ]. Lesion severity was categorized as one of three levels (mild, moderate, severe) by reviewing the imaging data [ 17 ].…”

“…The epidural injection level was chosen based on clinical manifestations, physical examination, and review of the imaging studies [ 17 ]. Lesion severity was categorized as one of three levels (mild, moderate, severe) by reviewing the imaging data [ 17 ]. This study was approved by our departmental ethics committee (KC20RIDI0315, SMC 2020-03-129) and registered with CRIS (Clinical Research Information Service of the Korea National Institute of Health, , KCT0004892).…”